Current extraction methods are often specific for a certain class of molecule, to the exclusion and loss of other classes of molecules. Often, a sample to be analyzed is limited in size, and extraction of one type of molecule exhausts the sample or prevents the extraction of additional classes of molecules from the sample. Liquid-liquid partitioning has been employed for extraction of molecular entities from complex mixtures based on the differential solubility of the molecules in different solvents. However, when immiscible or partially miscible solvents are used for liquid-liquid partitioning, the exchange between the solvents occurs only on the solvent interface, while the bulk of the solvents remaining isolated from interaction with each other. Partitioning of molecules between solvents, therefore, requires vigorous mechanical shaking to maintain a large liquid-liquid surface interface area between the solvents. Shaking of the solvents is typically conducted in separatory funnels and is performed with an excess of gas present in the funnel to facilitate the emulsification by shaking. Extracted molecules may be subject to air oxidation or otherwise affected by the presence of a gas phase, e.g., lather formation in the presence of detergents, therefore, rendering conventional liquid-liquid extraction process inconvenient, inefficient, or impossible.